The proper term for a ship's steering wheel is helm, although some refer to it as the ship's wheel as well. The wheel is usually connected to a mechanical, electrical or hydraulic system but, in some modern boats, the design uses a simple toggle to remotely control the rudder.
A traditional ship's wheel has eight cylindrical wooden spokes joined at a central hub. The spokes attach to an outer rim, creating a series of handles that a helmsman can use to help steer the ship. Traditional boats placed the helm at the back of the ship, so that the helmsman had the remainder of the ship at his back. Some ships have the helm at the front. Regardless, the steering works just as a car's steering works. The direction the wheel turns is the direction the boat will go.